This invention relates to a method for applying to a substrate a backing of a polymer derived from an organic polyisocyanate. More particularly, this invention relates to a method for preparing textiles backed with a polyurethane and/or polyurea polymer.
In the production of textiles, it is often desirable to provide the textile with a polymeric backing. The backing is useful for several purposes. It provides dimensional stability to the textile. It provides a cushion to the underside of the textile, thereby reducing or eliminating the need to use a separate padding when installing the textile. The backing often locks the fibers of the textile, particularly tufted or woven fibers, to a primary backing fabric. The backing also reduces wear on the primary backing fabric caused by contact with the underlayment and reduces the sliding of the textile over the underlayment during use.
The backing is particularly important in making modular carpet tiles. When such carpet tiles are installed, the adjacent tiles must fit together snugly so that the appearance of seams is negligible. This means that the modular carpet tiles must be highly dimensionally stable and that they lay flat on the floor without curling or otherwise becoming distorted.
Heretofore, the required dimensional stability was achieved by the use of a stabilizing scrim in the backing. Such scrim is typically a non-woven fiberglass mat which is embedded between two layers of a polymeric matrix. See, for example, U.S. Pat. No. 4,010,301 to Anderson et al. Although such scrim provides good dimensional stability, its use often makes the manufacture of the polymer backed textile more difficult and expensive. In addition, it is always of interest to improve the dimensional stability of the backed textile either with or without a scrim. It would therefore be desirable to provide a polymer-backed textile which is dimensionally stable without using such a scrim, and to improve the dimensional stability of a backed textile carpet containing a scrim.